Results 11 to 20 of about 2,548,043 (302)
Extreme Quasars as Distance Indicators in Cosmology
Frontiers in Astronomy and Space Sciences, 2020 Quasars accreting matter at very high rates (known as extreme Population A [xA] quasars, possibly associated with super-Eddington accreting massive black holes) may provide a new class of distance indicators covering cosmic epochs from present day up to ...
Deborah Dultzin +10 more
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Under-Developed and Under-Utilized Eclipsing Binary Model Capabilities [PDF]
Journal of Astronomy and Space Sciences, 2012 Existing but largely unused binary star model capabilities are examined. An easily implemented scheme is parameterization of starspot growth and decay that can stimulate work on outer convection zones and their dynamos.
R. E. Wilson
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Stark Broadening of Al IV Spectral Lines
Universe, 2023 Stark widths for 23 transitions in Al IV have been calculated by employing the modified semiempirical method. The results are obtained for an electron density of 1017 cm−3 and temperatures from 10,000 K to 160,000 K.
Milan S. Dimitrijević +1 more
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Semiclassical Stark Broadening Parameters of Ar VII Spectral Lines
Atoms, 2017 Using the semi-classical perturbation approach in the impact approximation, full width at half maximum and shift have been determined for eight spectral lines of Ar VII, for broadening by electron-, proton-, and He III-impacts.
Milan S. Dimitrijević +2 more
doaj +1 more source
Spectral Lines from Rotating Neutron Stars [PDF]
, 2002 The line profiles from rotating neutron stars are affected by a number of relativistic processes such as Doppler boosts, strong self-lensing, frame-dragging, and the differential gravitational redshift arising from the stellar oblateness. In this Letter,
Ozel, Feryal, Psaltis, Dimitrios
core +2 more sources
Measurement of Line Profiles [PDF]
Symposium - International Astronomical Union, 1986 The basic requirements for high precision spectral line profile measurements are reviewed, with the observatory at the University of Western Ontario serving to illustrate several of the points.
openaire +1 more source
Stark Broadening of Several Ar I Spectral Lines in the Visible Spectrum
Open Astronomy, 2011 In order to complete data on Stark broadening parameters for Ar I line in the visible spectrum, we determined Stark widths and shifts due to electron, proton and ionized helium impacts for nine lines (4191.0, 4259.4, 5912.1, 6043.2, 6045.0, 6752.9, 7503 ...
Dimitrijević Milan S. +3 more
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On the stark broadening of Os II spectral lines [PDF]
Bulletin of Natural Sciences Research, 2020 Stark broadening parameters, full widths at half maximum (FWHM) and shifts for 13 Os II lines have been calculated. The plasma parameters are: electron density of 1017 cm-3 and temperatures from 5 000 K to 80 000 K.
Dimitrijević Milan S.
doaj
Highlights of Astronomy, 1995 Observed hydrogen line profiles are an enormously important source of diagnostic information about virtually all kinds of astronomical bodies. Therefore, it is important to understand the hydrogen line formation in sufficient detail to be able to achieve a high degree of reliability by analyzing observed hydrogen line profiles.Calculation of the ...
openaire +1 more source
NLTE Analysis of High-Resolution H-Band Spectra, V: Neutral Sodium
Universe, 2023 In order to derive sodium abundances and investigate the effects of non-local thermodynamic equilibrium (NLTE) on the formation of H-band Na I lines, we update the sodium atomic model by incorporating collision rates with hydrogen from new quantum ...
Zeming Zhou +6 more
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